Senate leaders struck a bipartisan agreement Thursday to preserve the chamber’s filibuster but which limits how and when the minority party can use it.

The deal, which the full Senate easily approved Thursday evening, averted what could have become a poisonous parliamentary showdown known as the “nuclear option” that had Democrats changing the rules through a blunt majority vote.

Senate Majority Leader Harry Reid, Nevada Democrat, and Minority Leader Mitch McConnell, Kentucky Republican, struck the deal, which preserves the filibuster but gives the majority several options for how to get bills to the Senate floor. Right now, the minority party gets two opportunities to filibuster every bill, but the new deal could limit that to just one full filibuster, depending on circumstances.

“Ultimately, this might not solve all the problems, but it is a good-faith step in the right direction. It’s done in a bipartisan fashion,” said Senate Majority Whip Richard J. Durbin, Illinois Democrat. “I think it’s a positive thing for the Senate.”

The Senate approved the rule changes — divided into two bills — by votes of 78-16 and 86-9.

Some Democrats had wanted to see bigger changes and voiced disappointment that Mr. Reid didn’t go further.

Liberal groups took Mr. Reid to task over the deal, saying he squandered a golden opportunity to usher in bold reforms in a legislative body criticized as dysfunctional.

“Today’s agreement to enact incremental reforms to Senate rules, while containing some provisions that may prove to be of significant value in mitigating the calamitous mistreatment of judicial nominations, does not go as far as we would like,” said Nan Aron, president of the Alliance for Justice.

It takes 60 votes to overcome a filibuster — something that’s been difficult to muster amid Washington’s toxic partisanship in recent years.

Democrats have accused Mr. McConnell and fellow Republicans of abusing the tool, saying he has used it so excessively it has left the chamber mired in unprecedented gridlock. The GOP counters that Mr. Reid won’t allow any amendments on bills, breaking with Senate tradition and leaving Republicans no choice but to block the measures entirely.

Under terms of the compromise, the majority leader would have three options for bringing a bill to the floor. He could go the regular route, which would allow a minority filibuster; he could try to get agreement with Republicans, which would help him overcome an objection if it were just a handful of senators who were seeking a delay; or he could move to a bill on a simple majority vote, but would then have to guarantee at least two amendments to the minority side.

The agreement also limits the amount of time involved in filibusters of the president’s nominees.

Rule changes typically require a two-thirds majority, or 67 votes, in the 100-member Senate. But some liberal Senate Democrats pushing for sweeping filibuster reforms had pressed Mr. Reid to use the nuclear option — a parliamentary technique that could implement rule changes with only 51 votes.

Mr. Reid has said that while he had considered using the tactic, he preferred a bipartisan approach. Others in his caucus also were leery of using the maneuver because of the precedent it would set.